资料：Earlier this month, presidents Barack Obama of the US and Xi Jinping of China made an important symbolic gesture when they committed their countries, the two largest greenhouse gas emitters, to the Paris climate agreement. It was the clearest signal yet to investors worldwide that they need to think about the implications of global warming for their portfolios.

On Friday afternoon there was an example of what that might mean Mr Obama’s administration issued an order temporarily blocking construction on a section of the Dakota Access oil pipeline. The move was a response to local concerns raised by the Standing Rock Sioux Tribe about potential damage to historic sites and the threats of oil spills. But it is the global issue of climate change that had raised the profile of Dakota Access, making it into a cause celebre for US environmental campaigners. Bill McKibben of 350.org, which played a key role in the successful effort to stop the Keystone XL pipeline from Canada, has suggested that Mr Obama could block Dakota Access permanently, on the grounds that it would exacerbate the threat of climate change.

Last month, the White House’s Council on Environmental Quality issued new guidance for federal agencies, making clear that their decisions should take into account “the potential effects of a proposed action on climate change”, and quantify their consequences for greenhouse gas emissions. Dakota Access is intended to carry crude oil 1,172 miles from North Dakota, a centre of the US shale revolution, to Illinois, en route to refineries around America. The case that it would add to global greenhouse gas emission will be harder to make than for Keystone XL, which would have brought crude from the high-emitting oil sands of western Canada, but the campaigners are certain to try.

If Dakota Access is stopped, it will have a significant impact not just on energy Transfer Partners, the company leading the project, but on all North Dakota oil producers and their customers, who will be forced to use more expensive rail transport.

Climate change is now an unavoidable business issue. In an excellent paper last week, BlackRock, the world’s largest fund manager, set out some of the ways that investors can reduce their exposure to the risks and benefit from the opportunities that it creates. The paper is a landmark in the rising awareness of the issue among mainstream investors. It is one thing when a philanthropic fund with assets of a few hundred million takes a stand on climate issues, quite another when the warnings come from a company with about $4.9tn under management. As BlackRock points out, investors’ personal views on climate science are irrelevant. Enough governments and businesses are convinced by the scientific consensus that the threat is real, and are driving regulatory and technological changes that interested in you.

六If the world is to reduce the risk of catastrophic global warming to acceptable levels, there will have to be a huge reallocation of capital away from fossil fuels and toward low-emission energy sources. That shift has begun, but it needs to go much further. The transition is not straightforward: for as long as oil is the lifeblood of the world’s transport, pipelines will be needed. But when investors and boards make decisions about projects like Dakota Access, they will have to consider their impact on greenhouse gas emissions. The financial consequences of climate change can no longer be ignored.

Which one of the following is not the measure taken by US government to deal with climate change? （ ）.

• A.Stop the Dakota Access permanently
• B.Join the Paris climate agreement
• C.Require federal agencies to take climate change into consideration when making decisions
• D.Suspend the construction of Dakota Access